2565865 has 4 divisors (see below), whose sum is σ = 3079044. Its totient is φ = 2052688.

The previous prime is 2565863. The next prime is 2565881. The reversal of 2565865 is 5685652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 363609 + 2202256 = 603^2 + 1484^2 .

It is a cyclic number.

It is not a de Polignac number, because 2565865 - 2¹ = 2565863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2565863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256582 + ... + 256591.

It is an arithmetic number, because the mean of its divisors is an integer number (769761).

2^2565865 is an apocalyptic number.

It is an amenable number.

2565865 is a deficient number, since it is larger than the sum of its proper divisors (513179).

2565865 is an equidigital number, since it uses as much as digits as its factorization.

2565865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513178.

The product of its digits is 72000, while the sum is 37.

The square root of 2565865 is about 1601.8317639503. The cubic root of 2565865 is about 136.9024648986.

The spelling of 2565865 in words is "two million, five hundred sixty-five thousand, eight hundred sixty-five".